The molecularly imprinted polymers (MIP) were prepared via aqueous RAFT precipitation polymerization, with aristolochic acid I (AAI) as the template molecule, AA as the functional monomer , EGDMA as the cross-linker, AIBN as the chain initiator, CTP as the chain transfer agent and 80% (g/g) DMF-aqueous solution as the porogen . The differential UV–vis spectra revealed that a cooperative hydrogen-bonding complex between AAI and AA might be formed at the molar ratio of 1:3 in prepolymerized system. The synthesized MIPs were characterized by FTIR spectra, solid UV–visible absorption spectra, nitrogen adsorption-desorption isotherms and scanning electron microscope, which proved that the MIPs and NIPs have the similar chemical structures and the adding of AAI could affect the size and morphology of the microspheres . UV–visible absorption spectra and High-performance liquid chromatography (HPLC) was used to investigate the adsorption and recognition properties of the MIPs. The Scatchard isotherm model described that the binding sites independently acted. The Langmuir isotherm model suggested an excellent imprinting effect owing to the presence of a large number of specific binding sites on the MIP. The Freundlich model indicated that the AAI could be readily absorbed by MIP. Selective absorption of the template molecule was demonstrated in presence of its analogous compounds, benzoic acid and nitrobenzene . The recycling experiments implied that the MIP could be reused to further selective recognition and separation to AAI for six times at least. MIP was developed for removal of AAI from the Aristolochia manshuriensis extraction. The results indicated that 25 mg of MIP could remove the AAI below the HPLC detection limits (6.47 ng mL -1 ) from 5.0 mL of the extraction (CAAI=0.0018 mg mL -1 ) with the recovery of AAI to 91.50% (n=3, SD=4.24%). Therefore, it is clearly revealed that the MIP can be a useful tool to remove toxic compounds from natural products .
Shuang Han,Aixin Yao,Yuxin Ding,Qiuxue Leng,Fu Teng,Le Zhao,Ruonan Sun,Hongzhou Bu
In this study, a dual-template molecularly imprinted polymer (UIO-66@DMIPs) was synthesized using deep-eutectic solvents (DES) as functional monomer and doxorubicin (DOX) and phycocyanin (PC) as template molecules for the first time. The PC and DOX drugs were combined to obtain the synergistic effect by molecular imprinting technique (MIT). The novel deep-eutectic solvents (DES) as functional monomer can bind to the template molecules by electrostatic and hydrogen bonding forces to facilitate the formation of imprinted sites and increase the hydrophilicity of UIO-66@DMIPs, which improved the drugs release of UIO-66@DMIPs in aqueous media. The introduction of UIO-66-NH 2 in UIO-66@DMIPs reduced the encapsulation of the imprinted sites and resulted in better performance of the prepared UIO-66@DMIPs. The drugs-loaded UIO-66@DMIPs showed the maximum release of DOX and PC when the pH of the release medium was 5.0, with a release time of 20 h. UIO-66@DMIPs showed superior drugs loading and responsive drugs release for synergistic therapy during drugs delivery. As a drugs delivery system for compounded formulations, this study provides a reliable scheme with potential applications.
A series of novel dummy molecularly imprinted polymers (DMIPs) were prepared as highly class-selective sorbents for fluoroquinolones. A non-poisonous dummy template, daidzein, was used for the first time to create specific molecular recognition sites for fluoroquinolones in the synthesized polymers. The influence of porogen polarity on dummy molecular imprinting effect was studied. The DMIP prepared using dimethylsulfoxide−acetonitrile (1:1.8, v/v) as porogen achieved the highest imprinting factors (IF) for fluoroquinolones over a range of IF 13.4–84.0. This DMIP was then used for selective extraction of eight fluoroquinolones (fleroxacin, ofloxacin, norfloxacin, pefloxacin, ciprofloxacin, lomefloxacin, enrofloxacin and gatifloxacin) from fish samples based on dummy molecularly imprinted matrix solid-phase dispersion (DMI-MSPD). The extracted fluoroquinolones were subsequently analyzed by high-performance liquid chromatography (HPLC) equipped with a fluorescence detector (FLD). The developed method had acceptable recoveries (64.4−102.7%) and precision (RSDs: 1.7−8.5%, n = 5) for determination of fluoroquinolones in fish samples fortified at levels of 10 and 100 ng g −1 . The limits of detection (LODs) for identification of eight fluoroquinolones ranged between 0.06 and 0.22 ng g −1 . The results demonstrated great potential of the optimized method for sample preparation in routine analysis of trace fluoroquinolones in fish samples.
危险品化学品经营许可证（带存储）